A vehicle having a fuel cell that uses hydrogen gas as fuel gas causes a fuel tank to be charged with hydrogen gas, and runs while consuming the hydrogen gas. Thus, when the hydrogen gas in the hydrogen tank runs short, the vehicle needs to stop at a hydrogen supply station or the like to charge the hydrogen tank with hydrogen gas.
For example, Patent Document 1 describes that, as a hydrogen supply station, supply from a hydrogen supply tank is controlled based on the maximum working pressure of a vehicle-mounted hydrogen tank to be supplied hydrogen gas, using a tank specification determining means for determining the highest working pressure of a vehicle-mounted hydrogen tank. In the above, the shape of an earth adaptor for connection to an earth terminal provided to a vehicle differs from that of a vehicle-side earth terminal, depending on the highest working pressure of a vehicle-mounted hydrogen tank, and this is described as a tank specification determining means.
Patent Document 2 points out that, although mounting a plurality of tanks having different heat discharge characteristics on a vehicle is more efficient than mounting a single tank, in that respective characteristics can be utilized, it is not possible to carry out efficient charging when charging of the respective tanks begins at the same time, as the gas temperatures of the respective tanks increase by different amounts, and consequently, the tanks are non-uniform in gas charging efficiency. In view of the above, as a gas fuel charging method, it is described that charging pipes are connected to respective gas fuel charging ports of a plurality of tanks having different heat discharge characteristics, and that a charging channel switching means is provided to a vehicle so that gas fuel charging begins with a tank having a higher heat discharge characteristic.